This invention relates to a tool for installing wire coil screw thread inserts and, more particularly, to an improved power-driven installation tool for tangless wire coil inserts.
Tools for the installation of wire coil inserts having at one end a diametrical tang of its end convolution so arranged so that the tang can be gripped by the tool as it projects from the coil for installation into a tapped hole are described, e.g., in U.S. Pat. No. 3,111,751. However, the tools are not compatible with tangless wire coil inserts.
The prior art insertion tools, however, generally comprise complicated devices in which the prewinder, used for contracting the original oversized insert to a smaller diameter, does not permit the insert to properly engage the first threads of the patent material. These prior art devices further do not provide for reversing the torque and removing the mandrel from the insert after it has been installed to its proper predetermined depth.